From: Jason Gunthorpe jgg@mellanox.com
commit f2f2b3bbf0d9f8d090b9a019679223b2bd1c66c4 upstream.
If name memory allocation fails the name will be left empty and device_add_one() will crash:
kobject: (0000000004952746): attempted to be registered with empty name! WARNING: CPU: 0 PID: 329 at lib/kobject.c:234 kobject_add_internal+0x7ac/0x9a0 lib/kobject.c:234 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 329 Comm: syz-executor.5 Not tainted 5.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x3e kernel/panic.c:582 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:kobject_add_internal+0x7ac/0x9a0 lib/kobject.c:234 Code: 1a 98 ca f9 e9 f0 f8 ff ff 4c 89 f7 e8 6d 98 ca f9 e9 95 f9 ff ff e8 c3 f0 8b f9 4c 89 e6 48 c7 c7 a0 0e 1a 89 e8 e3 41 5c f9 <0f> 0b 41 bd ea ff ff ff e9 52 ff ff ff e8 a2 f0 8b f9 0f 0b e8 9b RSP: 0018:ffffc90005b27908 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815eae46 RDI: fffff52000b64f13 RBP: ffffc90005b27960 R08: ffff88805aeba480 R09: ffffed1015d06659 R10: ffffed1015d06658 R11: ffff8880ae8332c7 R12: ffff8880a37fd000 R13: 0000000000000000 R14: ffff888096691780 R15: 0000000000000001 kobject_add_varg lib/kobject.c:390 [inline] kobject_add+0x150/0x1c0 lib/kobject.c:442 device_add+0x3be/0x1d00 drivers/base/core.c:2412 add_one_compat_dev drivers/infiniband/core/device.c:901 [inline] add_one_compat_dev+0x46a/0x7e0 drivers/infiniband/core/device.c:857 rdma_dev_init_net+0x2eb/0x490 drivers/infiniband/core/device.c:1120 ops_init+0xb3/0x420 net/core/net_namespace.c:137 setup_net+0x2d5/0x8b0 net/core/net_namespace.c:327 copy_net_ns+0x29e/0x5a0 net/core/net_namespace.c:468 create_new_namespaces+0x403/0xb50 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:229 ksys_unshare+0x444/0x980 kernel/fork.c:2955 __do_sys_unshare kernel/fork.c:3023 [inline] __se_sys_unshare kernel/fork.c:3021 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3021 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Link: https://lore.kernel.org/r/20200309193200.GA10633@ziepe.ca Cc: stable@kernel.org Fixes: 4e0f7b907072 ("RDMA/core: Implement compat device/sysfs tree in net namespace") Reported-by: syzbot+ab4dae63f7d310641ded@syzkaller.appspotmail.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/device.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/core/device.c +++ b/drivers/infiniband/core/device.c @@ -899,7 +899,9 @@ static int add_one_compat_dev(struct ib_ cdev->dev.parent = device->dev.parent; rdma_init_coredev(cdev, device, read_pnet(&rnet->net)); cdev->dev.release = compatdev_release; - dev_set_name(&cdev->dev, "%s", dev_name(&device->dev)); + ret = dev_set_name(&cdev->dev, "%s", dev_name(&device->dev)); + if (ret) + goto add_err;
ret = device_add(&cdev->dev); if (ret)